Means for supporting and sealing retractable soot blowers



Aug. 27, 1957 LE ROY 5, DE MART 2,803,848

MEANS FOR SUPPORTING AND SEALING RETRACTABLE 500T BLOWERS 2 Sheets-Sheet l F1168 Sept. so. 1953 INVENTOR. v XF/T'ag] -fife Kari Aug. 27, 1957 MEANS FOR SUPPORTING AND SEALING RETRACTABLE SOOT BLOWERS Filed Sept. 30, 1953 LE ROY 5. DE MART 2 Sheets-Sheet 2 INVENTOR.

%W,2%y 4 mg United States atent MEANS FOR SUPPORTING AND SEALING RETRACTABLE SOOT BLOWERS Le Roy S. De Mart, Lancaster, Ohio, assignor to Diamond Power Specialty Corporation, Lancaster, @hio, a corporation of Ohio Application September 30, 1953, Serial No. 383,354 '9 Claims. or. 154.17

This invention relates to soot blowers and, more particularly, to an improved means for supporting and sealing retractable soot blowers and the like.

An object of the invention is to overcome disadvantages in prior soot blowers of the indicated character and to provide improved apparatus for supporting and sealing retractable soot blowers so as to prevent the escape of gases from the boiler furnace through the opening that is provided in the furnace wall to accommodate the lance tube of a retractable soot blower.

Another object of the invention is to provide improved apparatus for supporting and sealing retractable soot blowers of the type adapted for use on positive pressure boilers.

Another object of the invention is to provide improved apparatus for supporting and sealing retractable soot blowers that prevents the escape of gases through the and assemhled and which is durable, efficient and reliable i in operation Yet another object of the invention is to provide improved supporting and sealing apparatus for retractable soot blowers which may be incorporated in the wall box of a boiler furnace and which operates at a relatively low temperature.

A In the accomplishment of these objects, the present invention provides an annular chamber which surrounds the lance tube of a retractable soot blower adjacent the wall box end thereof and in which air is maintained under pressure in excess of the pressure in the boiler furnace. Since" the operating pressure of the furnace is greater than the ambient atmospheric temperature, the present invention provides means which compensates for such diiterence in pressure and enables approximately the same amount of pressurized sealing air to flow from the aforementioned annular chamber through the wall box into the furnace as flowsfrom the chamber to the atmosphere, thereby providing an air seal which effectively prevents the escape of hot gases from the furnace.

The present invention also provides a novel and improved supporting arrangement whereby the lance tube is supported so that it may pivot about both the horizontal, axis and. the vertical axis of the aforementioned air. seal so. that all relative angular movement between the. lance tube and the. wall box takes place about the center 65 the air. seal. In addition, the present invention provides means for forming an air seal in the event the lance tube of a s oot blower is completely removed H from the Wall box of a boiler furnace, as for repair or replacement.

The above as well as other objects and advantages of the invention will become apparent from the following description, the appended claims and the accompanying drawing wherein:

Figure 1 is a side elevational view of a soot blower sealing and supporting installation incorporating the present invention, with portions in section and other portions broken away, as applied to the lance tube of a soot blower;

Fig. 2 is a sectional view of the structure illustrated in Fig. 1, taken on the line 2-2 thereof and looking in the direction of the arrows; and

Fig. 3 is a side elevational view of a portion of the structure illustrated in Fig. 1.

Referring to the drawing, a preferred embodiment of the invention is shown incorporated in a seal and support for a retractable soot blower of a known type which is shown in installed relationship with respect to a fragmentarily illustrated boiler. The details of the boiler and soot blower form no part of the present invention and while a long travel blower is shown, this is merely to typify an important use of the invention. The blower installation includes a stationary, horizontally extending I-beam 10 which projects outwardly from the boiler in a direction substantially perpendicular to the boiler wall 12. A rotatable and retractable lance tube 14 is supported by the I-beam id in a manner which will be explained hereinafter in greater detail and is projectable into and retractable from the boiler furnace through a wall box, generally designated 16, that is also carried by the I-beam 10. Rotational and sliding movement is imparted to the lance tube by any suitable or conventional driving means (not shown) and when the blower is operated, compressed air, steam, solid pellets or other cleaning medium is supplied through the lance tube 14 and discharged from the nozzle end 17 thereof against the boiler surfaces to be cleaned, which may include the water wall tubes, such as 18. I p

The wall box 16 is comprised of a housing 20 which defines a horizontally extending passageway 22 that is coaxial with, but somewhat larger in diameter than, the lance tube 14 so that the nozzle endof the lance tube may pass through the passageway 22 into the boiler fur nace. The housing 20 also defines a pair of annular chamhers 24 and 26 which are spaced longitudinally of the passageway 22 adjacent the outer end thereof. A sleeve member 28 having an outwardly extending flange portion 30 is fitted in the passageway 22 and secured to the end wall 32 of the housing2 0 by bolt, such as 34, which pass through the flange portion 30 and threadably engage openings in the wall 32. The sleeve member 28 is provided with an internal annular groove 36 having circumferentially spaced holes 38 therein communicating with the chamber 24. Pipe fitting socket openings, such as 4;) and 42, are formcd'in the sidewall 44 of the housing 29 and a supply pipe, such as 46, is connected to the most readily accessible socket opening in the particular installation, the other socket openings being, of course, plugged. Compressed air is fed to the chamber 24 through the pipe 46 and then passes through the holes 38 and along the periphery of the lance tube 14 which passes through the sleeve member 28. The internal diameter of the. portion of the sleeve member between the groove .36 and the furnace wall 12 is somewhat greater than the internal diameter of thesleeve portion. between theintern-al groove .36 and the atmosphere. Greater, clearance is therebyprovided in the annular area designated 481.1betvveenthe lance tube and the; furnace end of the sleeve member, 28 thani s provided in the annular area designated 50 between the lance tube and the outer end. portion of the sleeve member. The air pressure at 48 is somewhat greater than the operating pressure of the furnace which, in turn, is greater than the ambient atmospheric pressure .at 50 and the clearance areas 48 and 50 are proportioned so that approximately the same amount of air flows from the chamber 24 through the holes 38, along the periphery of the lance tube and through the clearance area 48 into the wall box passageway 22 as flows from the chamber 24 through the holes 38, along the periphery of the lance tube and through the clearance area at 50 to the atmosphere.

The compressed air flowing into the furnace through the clearance area 48 forms an air seal which prevents the escape of hot gases from the furnace. In the event the lance tube becomes bent or warped, the two clearance areas Will remain substantially proportionate and the compressed air will continue to flow into the furnace to prevent the escape of hot gases.

For the purpose of preventing the escape of gases from the furnace in the event the lance tube 14 is completely withdrawn from the wall box, as for repair or replacement, a bushing member 52 is fitted in the passageway 22 of the housing 20. The bushing member 52 is coaxial with but slightly larger in diameter than the sleeve member 28 and is adapted to receive the lance tube 14. One end of the bushing member 52 abuts the web portion 54 of the housing intermediate the chambers 24 and 26 While the other end portion of the bushing member is provided with tongues, such as 55, which may be welded or otherwise secured to the wall water tubes 18. A relatively large number of closely peripherally spaced inwardly convergent duct openings 56 extend through the wall of the bushing 52 and communicate with the chamber 26. Compressed air is adapted to be supplied to the chamber 26 through a supply pipe 58 threadably connected to the housing, as at 60. The compressed air is discharged from the chamber 26 through the holes 56 in the form of a cone-like screen at suflicient velocity and pressure to prevent outflow of furnace gases therethrough even if the lance tube is backed away from servicing. A suitable hand valve (not shown) may enable control of the air supply to the air screen discharge openings 56, as will be apparent. It has been found desirable to allow discharge of a slight amount of air through the openings 56 at all times while the boiler is in service to protect the openings 56 against fouling.

When the boiler is in operation, the furnace walls expand and contract because of the thermal and vibration stresses therein and in order to maintain a close fit between the lance tube 14 and the sleeve 28 with a minimum of clearance, the present invention provides a support assembly for the wall box 16 and the lance tube 14 which forces all relative angular movement between the lance tube and the wall box to take place about the center of the air seal ring intermediate the annular areas designated 48 and 50. The support assembly is comprised of an outwardly extending bracket 62 which is secured to the web portion 64 of the I-beam ajacent the furnace 'end thereof by bolts 66 or other suitable means. The bracket 62 defines a vertically extending passageway 68 and a pivot pin 70 extends through and is journaled for oscillation in the passageway 68,the pin being retained by a nut 72 or other suitable means. The upper end portion 74 of a support member, generally designated 76, is offset with respect to the central portion 78 thereof and defines a passageway 80 into which the lower end portion of the pin 70 is press-fitted or otherwise secured so that the pin 70 is fixed to the support member 76. The bracket 62 and support member 76 are so proportioned to the wall box 16 that the longitudinal axis of the pin 70 is substantially vertical and is disposed in a transverse vertical plane which passes through the centers of the holes 38 in the sleeve member 28, the axis of the pin 70 also being co-planar with the longitudinal axis of the sleeve 28. The central portion 78 of the support member 76 is provided with an opening 82 that is coaxial with and slightly larger in diameter than the flange 30 of the sleeve member 28 so that the sleeve member may be fitted through the opening 82. A pair of flanges 84 and 86 project toward the furnace wall 12 from opposite sides of the opening 82 in the support member 76. The flanges 84 and 86 are provided with openings 88 and 90, respectively, and headed pivots pins 92 and 94 pass through the openings 88 and and threadably engage apertures provided in bosses 96 and 98 on opposite sides of the housing 16. The longitudinal axes of the pins 92 and 94 lie in a horizontal plane which passes through the longitudinal axis of the sleeve member 28 and also lie in a vertical plane which passes through the centers of the holes 38 in the sleeve member 28. Since the longitudinal axis of the pin 76 is disposed at the intersection of a transverse vertical plane which passes through the centers of the holes in the sleeve member 28 and a vertical plane which passes through the longitudinal axis of the sleeve member 28 and since the axes of the pivot pins 92 and are disposed at the intersection of a horizontal plane which passes through the longitudinal axis of the sleeve member 28 and a vertical plane which passes through the centers of the holes 38 such a construction forces all relative angular movement between the wall box 16 and the lance tube 14 to take place about the center of the air seal ring intermediate the annular areas designated 48 and 58, thereby reducing the relative angular movement between the lance tube and the air seal ring to a minimum when the boiler wall 12 expands and contracts and enabling the clearance between the sleeve member 28 and the lance tube 14 to be reduced to a minimum.

The support member 76 carries a pair of oppositely dis posed, inwardly extending brackets 100 and 102, the outer end portions of which are pivotally connected to the support member by pivot pins 104 and 106. The inner ends of the pins 194 and 1&6 threadably engage the support member 76 and the brackets 100 and 102 are retained on the pins 104 and 106 by cotter pins, such as 108, or other suitable means. A pair of tapered rollers 110 and 112 are rotatably mounted on roller pins 114 and 116 which, in turn, are mounted in the inner end portions of the brackets 100 and 102, respectively, the roller pins 114 and 116 being secured by setscrews 118 threadably fitted in the brackets 100 and 192 and engaging a recess provided in each of the pins 114 and 116.

Since the lance tube 14 is rotated in one direction during the projection into the furnace and is rotated in the opposite direction during the retraction from the furnace, the axes of the rollers 110 and 112 are set at an angle to the longitudinal axis of the lance tube 14, the angle corresponding to the pitch of the helix represented by such rotary and longitudinal movement of the lance tube so as to reduce the frictional contact between the rollers and the lance tube. Because of the angular positioning of the rollers, they are formed in the shape of a truncated cone to insure substantially line contact with the lance tube 14.

The inner end portions of the brackets 100 and 102 are supported on adjusting bolts 119 and 120 threadably fitted in a horizontally projecting flange 122 provided on the lower end portion of the support member 76 and the bolts 119 and 120 may be locked in the selected adjusted position by means of lock nuts 124.

From the above description it will become apparent that the entire sealing and supporting apparatus will operate at a relatively low temperature because of the flow of air therethrough and therearound and because of the cooling effect obtained as the compressed air expands to the lower pressures, thereby insuring relatively long life for the assembly.

While a preferred embodiment of the invention has been shown and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.

What is claimed is:

1. In combination with a lance tube projectable into and retractable from a boiler'furnace, a housing encompassing said 1 nce tube adjacent said furnace, said housing'havihg a chamber thereinwherein air is maintained under pressure exeess of'tlie pressure in said furnace, inea'nsfor formingan air seal within said housing so as to compensate for the difference in pressure of the gases in said furnace and the'pre'ssure of the ambient atmosphere whereby a portidn of the an in said chamber flows into said furnace and opposes Communication of such gases 'withthe atmosphere, and 'means supporting said lance tube for a pivotal movement about a predetermined point'w'ithin the air'seal formed in said housing.

21in combination with a lance tube projectable into and retractable from a boiler 'fu'rnace, a housing having a bore therethroilg'l and an annular chamber wherein air' is maintained under pressure in excess of the pressure in said furnace, asle'evefitted in said bore and receiving said lance tube, saidsleevehaving a'plurality of circumferent'ially spaced openings in the wall thereof communi eating with said chamber, means controlling the flow of air from said chamber through said openings into said furnace whereby said air opposes communication of the furnace gases with the atmosphere, and means supporting said lance tube for relative pivotal movement about a predetermined point disposed in a plane passing through the circumferentially spaced openings in said sleeve;

3. In combination with a lance tube projectable into and retractable from a boiler furnace, means for preventing the escape of gases from saidfurnace along the periphery" of said lance tube, said means comprising a housing having a substantially horizontally extending bore and an annular chamber wherein air is maintained under pressure in excess of the pressure in said furnace, a sleeve member fitted in said bore and receiving said lance tube, said sleeve member having a plurality of circumferentially spaced openings centrally of the ends thereof and communicating with said chamber, means controlling the flow of air from said chamber through said openings into said furnace, whereby said air opposes communication of such gases with the atmosphere, and means supporting said lance tube for relative pivotal movement about a predetermined point disposed in a plane passing through the circumferentially spaced openings in said sleeve.

4. In combination with a lance tube projectable into and retractable from a boiler furnace, means for pre venting the escape of gases from said furnace along the periphery of said lance tube, said means comprising a housing having a substantially horizontally extending bore and an annular chamber wherein air is maintained under pressure in excess of the pressure in said furnace, a sleeve member fitted in said bore and receiving said lance tube,

said sleeve member having a plurality of circumferentially spaced openings centrally of the ends thereof and communicating with said chamber, means controlling the flow of air from said chamber through said openings into said furnace, whereby said air opposes communication of such gases with the atmosphere, means supporting said lance tube for relative pivotal movement about a predetermined point within said sleeve, said supporting means including a fixed structural member, a support member pivotally connected to said structural member for pivotal movement about an axis disposed in a substantially vertical plane passing through said openings in said sleeve, means connecting said support member to said housing for pivotal movement about an axis substantially perpendicular to said first-mentioned axis, a pair of oppositely disposed brackets pivotally attached at the outer end portions thereof to said support member, a pair of rollers rotatably mounted on the inner end portions of said brackets and engaging and supporting said lance tube, and means secured to said support member for supporting said brackets in an angularly adjusted position. I

5. In combination with a lance tube pro ectable into and retractable from a boiler furnace, means for preventing the escape of gases from said furnace along'th eperiphery of said lance tube, said means comprising a hous ing having a substantially horizontally extending bore and an annular chainber wherein air is maintained under pressure in excess of the pressure in said furnace, a sleeve member fitted in said bore and receiving said lancetube, said sleeve member having a plurality of circumferentially spaced openings centrally of the ends thereof and communicating with said chamber, means controlling the flow of air from said chamber through said openings into said furnace, whereby saidair opposes communication of such gases with the atmosphere, means supporting said lance tube for relative pivotal movement about a predetermined point within said sleeve, said supporting means including a fixed structural member, a support member pivotally connected to said structuralmernber for pivotal movement about an axis disposed in a substantially vertical plane passing through said openings in said sleeve, means connecting said support member to said housing for pivotal movement about an axis substantially perpendicular to said first-mentioned axis, a pair of oppositely disposed brackets pivotally attached at the outer end portions thereof to said support member, apair of tapered rollers rotatably mounted on the inner end portions of said brackets and engaging and supporting said lance tube, the axis of each of said rollers offset with respect to the axis of said lance tube, and means secured to said support member for supporting said brackets in an angularly adjusted position. i i

6. In a sealing and supporting device for soot blowers and the like, the combinationincluding a wall box having an annular chamber therein, means for supplying compressed air to said chamber, a horizontally extending sleeve member fitted in said wall box and adapted to accommodate therein a lance tube, the bore at the outer end portion of said sleeve member being reduced in diameter, said sleeve member also provided with a plurality of circumferentially spaced openings intermediate the reduced diameter portion thereof and the inner end thereof, the openings in the sleeve member interconnecting said bore with said chamber, and means for supporting said lance tube for pivotal movement about a predetermined point disposed in a plane passing through the circumfera entially spaced openings in said sleeve.

7. In a sealing and supporting device for soot blowers and the like, the combination including a wall box having an annular chamber therein, means for supplying compressed air to said chamber, a horizontally extending sleeve member fitted in said wall box and adapted to accommodate therein a lance tube, the bore at an outer end portion of said sleeve member being reduced in diameter, said sleeve member also provided with a plurality of circumferentially spaced openings intermediate the reduced diameter portion thereof and the inner end thereof, the openings in the sleeve member interconnecting said bore with said chamber, means for supporting said lance tube for pivotal movement about a predetermined point Within said sleeve, said supporting means including a fixed structural member, a support member pivotally connected to said structural member for pivotal movement about a substantially vertical axis disposed in a. plane passing through the centers of the openings in said sleeve, means connecting said support member to said wall box for pivotal movement about a substantially horizontal axis intersecting said first-mentioned axis, a pair of oppositely disposed brackets pivotally attached at the outer end portions thereof to said support member, a pair of tapered rollers rotatably mounted on the inner end portions of said brackets and adapted to engage and support said lance tube, the axis of each of said rollers offset with respect to the axis of said lance tube when mounted thereon, and means secured to said support member for supporting said brackets in an angularly adjusted position.

8. In a sealing and supporting device for use with a soot blower and the like, the combination comprising a wall box having a pair of spaced annular chambers therein, a horizontally extending sleeve member fitted in said wall box and adapted to accommodate the lance tube of said soot blower, the bore at the outer end portion of said sleeve member being reduced in diameter, said sleeve member also provided with a plurality of circumferentially spaced openings intermediate the reduced diameter portion thereof and the inner end thereof, the openings in the sleeve member interconnecting the bore thereof With one of said chambers, a bushing member fitted in said wall box in axially spaced relationship with respect to said sleeve member, said bushing member having a plurality of circumferentially spaced inclined openings interconnecting the bore thereof'with the other of said chambers, means for supplying compressed air to said chambers, and means for supporting said lance tube for relative pivotal movement about the center of the group of openings in said sleeve member.

9. In a sealing and supporting device for use with a soot blower and the like, the combination comprising a housing having a pair of spaced annular chambers therein, a horizontally extending sleeve member fitted in said housing and adapted to accommodate the lance tube of said soot blower, the bore at the outer end portion of said sleeve member being reduced in diameter, said sleeve member also provided with a plurality of circumferentially spaced openings intermediate the reduced diameter portion thereof and the inner end thereof, the openings in the sleeve member interconnecting the bore thereof with one of said chambers, a bushing member fitted in said housing in axially spaced relationship with respect to said sleeve member, said bushing member having a plurality of circumferentially spaced inclined openings interconnecting the bore thereof with the other of said chambers, means for supplying compressed air to said chambers, means for supporting said lance tube for relative pivotal movement about the center of the group of openings in said sleeve member, said supporting means including a fixed structural member, a support member pivotally connected to said structural member for pivotal movement about a substantially vertical axis disposed in a plane passing through the centers of the openings in said sleeve, means connecting said support member to said housing for pivotal movement about a substantially horizontal axis intersecting said first-mentioned axis, a pair of oppositely disposed brackets pivotally attached at the outer end portions thereof to said support member, a pair of tapered rollers rotatably mounted on the inner end portions of said brackets and adapted to engage and support said lance tube, the axis of each of said rollers otfset with respect to the axis of said lance tube when mounted thereon, and means secured to said support member for supporting said brackets in an angularly adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS 966,051 Reiter Aug. 2, 1910 1,010,028 Davies Nov. 28, 1911 1,874,151 Arey Aug. 30, 1932 2,089,710 Reekie Aug. 10, 1937 2,444,211 Wager June 29, 1948 2,477,334 Hibner July 26, 1949 2,532,447 Handoll et a1. Dec. 5, 1950 2,545,886 Kooistra Mar. 20, 1951 FOREIGN PATENTS 567,351 Germany Dec. 30, 1932 

